Mismatched speed rating on tires a problem?

[pet575]

I have just bought 3 new 245/65R17's for my '04 LTD AWD. The spare was the same, and they are BF Goodrich Radial T/A. Same tread pattern, all have same tread depth. Only difference is the 3 new tires have "T" speed rating and the other tire has an "S" rating.

Anyone think it will be a problem to run all of these tires together? This is, of course, assuming I am driving within the speed rating of the lowest rated tire.

 

[RickM]

This is, of course, assuming I am driving within the speed rating of the lowest rated tire.

Bingo, while it is a mismatched, older tire.....should be no prob at all.

 

[techieman33]

Agreed, shouldn't be an issue, I doubt you'll ever go fast enough to even have to worry about the speed ratings.

 

[SuRrEaLNJ]

S is rated to 112. T is rated to 118mph, so providing you keep it under 112 then you should be good.

id eorry more about load rating and tread compound then anythign else though. chances are you wont notice any difference, but i tend to be **** about tires.
for what its worth we have customers all the time come in with mis matched brands/types/ratings/sizes etc...

 

[skibum]

The speed is not so much a concern. Tires should be perfectly matched on late model Ford Explorers with four wheel drive or else risk damaging the transmission. The diamater of each tire and rev per tire must be the same on all four tires. If the tire weight, drag, or diamater is mismatched the computer can start to detect slipage and make adjustments continueously that damage the transmission. I would check with BFGoodrich to see if the weight, revs, diamater, and rolling resistance are the same. Just allowing one or two tires to wear unevenly can cause transmission problems. You always swap out four tires at a time in an AWD vehicle, but in your case you may have four identical tires. If you feel the SUV hesitating or uneven linkage, especially on a hill, that is a symptom.